The present invention relates to a process for the telomerization of a conjugated diene, and a catalyst and bidentate ligand that can be used in this process.
WO-A-9210450 describes a telomerization reaction wherein 1,3-butadiene is reacted with a compound containing an active hydrogen atom and having a formula Rxe2x80x94H in the presence of a telomerization catalyst to form a 1-substituted-2,7-octadiene of formula CH2xe2x95x90CHxe2x80x94CH2xe2x80x94CH2xe2x80x94CH2xe2x80x94CHxe2x95x90CHxe2x80x94CH2xe2x80x94R, in which R represent the residue of the compound containing an active hydrogen atom. WO-A-9210450 describes telomerization catalysts such as the transition metals Fe, Co, Ni, Ru, Rh, Pd, Os, Ir and Pt (Group VIII transition metals) and compounds thereof, including those supported on an inert carrier, as well as ligand compounds including diphosphines.
However, it is desirable to provide a process for the telomerization of a conjugated diene, wherein the telomerization reaction can be carried out with an improved selectivity towards the linear telomerization product.
Accordingly, a process for the telomerization of a conjugated diene is provided, comprising:
reacting the conjugated diene with a compound containing an active hydrogen atom and having a formula Rxe2x80x2xe2x80x94H in the presence of a telomerization catalyst based on:
(a) a source of group VIII metal,
(b) a bidentate ligand
wherein the bidentate ligand has the general formula I
R1R2M1xe2x80x94Rxe2x80x94M2R3R4xe2x80x83xe2x80x83(I) 
wherein M1 and M2 are independently P, As or Sb;
R1, R2, R3 and R4 independently represent a monovalent aliphatic group;
or R1, R2 and M1 together and/or R3, R4 and M2 together independently represent an optionally substituted aliphatic cyclic group with at least 5 ring atoms,
wherein one ring atom in said cyclic group is M1 or M2;
and R represents a bivalent organic bridging group.
In addition, a process for the preparation of 1-octene is provided, comprising:
a) reacting 1,3-butadiene with a compound containing an active hydrogen atom and having a formula Rxe2x80x2xe2x80x94H in the presence of a telomerization catalyst based on:
(1) a source of group VIII metal,
(2) a bidentate ligand
wherein the bidentate ligand has the general formula I
R1R2M1xe2x80x94Rxe2x80x94M2R3R4xe2x80x83xe2x80x83(I) 
wherein M1 and M2 are independently P, As or Sb;
R1, R2, R3 and R4 independently represent a monovalent aliphatic group;
or R1, R2 and M1 together and/or R3, R4 and M2 together independently represent an optionally substituted aliphatic cyclic group with at least 5 ring atoms,
wherein one ring atom in said cyclic group is M1 or M2;
and R represents a bivalent organic bridging group; thereby producing 1-substituted-2,7-octadiene;
b) hydrogenating the 1-substituted-2,7-octadiene of step a), thereby producing 1-substituted octane;
c) decomposing the 1-substituted octane of step b), thereby producing 1-octene.
Also provided are catalyst systems and bidentate ligands useful in the processes of the present invention.